1. Field of the Invention
The present invention relates to a mobile terminal device, a program storage medium, and an information displaying method for displaying information for a user in a part of a display area, which is not covered with a radio frequency identification (RFID) tag.
2. Description of the Related Art
In recent years, attention has been paid to mobile terminal devices that can perform close-proximity wireless communication, exchanging information with RFID tags by means of RFID. RFID is an authentication technique that utilizes electromagnetic waves. The RFID tag uses the RFID technique, and can perform close-proximity wireless communication to exchange information. The RFID tag is a contactless smartcard or an RFID tag, in which an antenna and electronic elements, including an IC chip, are embedded.
The use of mobile terminal devices using RFID renders it easy to achieve inventory management of merchandise items, each having an RFID tag attached to it. Further, the key information items recorded in the RFID tag can facilitate electronic money transactions. In addition, once the ID code of the user has been stored in the mobile terminal, the user's entry and exit can be managed more easily than otherwise.
RFID using the frequency band of 13.56 MHz will be described. In RFID using the frequency band of 13.56 MHz, each mobile terminal device has a loop antenna, and the electromagnetic induction system is employed.
The electromagnetic induction system is characterized in that:
(1) The communication distance is small, 0 to 20 mm; and
(2) A metal member, if any existing close to the antenna of the mobile terminal device or between the device and the RFID tag, intercepts the electromagnetic wave output from the device, disabling the communication.
In connection with a mobile terminal device designed in consideration of these characteristics (1) and (2), PCT National Publication No. 2007-536665, for example, describes an electronic device having a display unit for displaying the position index that indicates the position in the device, where communication is performed. That is, this publication discloses a technique of causing the display unit to display the position the antenna assumes in the mobile terminal device.
Most mobile terminal devices having a display unit have a loop antenna that extends along the outer periphery of the display unit. Since the loop antenna so extends, the display unit has a sufficiently large display area, there is no need to provide an extra space for the loop antenna. The mobile terminal device can therefore be made smaller than otherwise. Among the mobile terminal devices now available are a personal digital assistant (PDA) and a handy terminal.
If the technique disclosed in PCT National Publication No. 2007-536665 is applied to the mobile terminal device described above, the display area of the display unit may be covered with the RFID tag held to transfer information to the mobile terminal device. Then, the user cannot see the information the display unit is displaying. The display unit is designed to display a read instruction “Hold your card over the device,” a read result message “Information read OK,” and card positioning instruction “Move your card a little.” Most smartcards used as RFID tags have a size of 85.6 mm×54 mm, or about 4-inch screen size. The smartcard may therefore cover a greater part of the display unit of the mobile terminal device, which is limited in size. Consequently, the user may not see the information the display unit displays.